Types of angles

Two line segments that share a common endpoint form an angle. The common point (looks like the "corner") is called the vertex.

The figure to the right shows an angle. The angle is called "Angle CAB" and is written $\angle{CAB}$ because it is made up of the three points C, A, and B. The angle could also be called $\angle\,BAC$. Note that in both ways to name the angle the A is in the middle because it is the vertex.

The green arc betwen the two line segments is the angle and is used to highlight the distance between the two sides of the angle.

Directions:

Move point C and notice how the degrees change. As the degrees change, the type of angle will also change.

You will see that there are five types of angles: acute, right, obtuse, straight, and reflex.